Preparation And Magnetic Characteristics Analysis Of AlN Film Diluted Magnetic Semiconductors

Ni-doped AlN films were successfully prepared by radio frequency reactive sputtering.All of the film grew along the crystal lographic orientation AlN(100),but the sample Al0.953Ni0.047N exist the phase of AlNi3. Ni atoms have been incorporated into AlN lattice as Ni3+substituting for Al3+ions.All the sample had ferromagnetism at room temperature. Saturation magnetization and coercivity of the samples have a tendency to increase with the increasing addition of Ni,the maximum saturation magnetization and coercivity reach64.5emu/cm3and104Oe when x=0.082. Ferromagnetism is an intrinsic property of Ni-doped AlN films,not from any secondary phase,such as Ni clusters and NiO. Bound magnetic polaron models may provide an explanation for the ferromagnetisms observed in our samples.Room temperature(RT)ferromagnetisms were also firstly realized in Mg-doped AlN films by radio frequency reactive sputtering.The film grew along the crystallographic orientation AlN(002) change to AlN(100) with the increasing addition of Mg.There is a critical value(x=0.187),if the doping amount exceeds it,the film will grow along the crystallographic orientation AlN(002) also AlN(100) and the doped Mg will exist as Mg clusters in AlN crystal. The Mg atoms can successfully incorporated into AlN lattice and substitute for Al atom with suitable addition of Mg such as x=0.106. All the sample had ferromagnetism at room temperature, the maximum saturation magnetization and coercivity reach60.2emu/cm3and186Oe. Ferromagnetism is an intrinsic property of Mg-doped AlN films,not from any secondary phase,such as Mg clusters and MgO. It is believed that the defects have great contribution for ferromagnetic order in Mg-doped.